The present invention relates to telecommunications networks and more particularly to services provided by such networks.
The public switched telephone network (PSTN) is capable of providing customers with many services other than basic telephony. Digital networks such as that provided by BT in the United Kingdom have the ability to effect call connection very quickly. Thus dual tone multi frequency (DTMF) signalling from customers before, during or on termination of telephone calls can be used to connect special services. Further, special service platforms may be called by customers requesting connection to specified network numbers to provide additional services.
One service provided by the PSTN in the United Kingdom allows customers to identify a calling party's telephone number either using a display unit which is signalled when a call is offered or by calling a code to be advised of the latest call made. The customer may wish to know more about the source of the received call prior to making a return call as a result of the caller display service or as a result of a mailbox or answering machine message requests a return call.
Similarly, prior to making a call to a known telephone number the customer may wish to consider the likely cost involved or special factors associated with the telephone number such as the type of destination.